Accurate identification of adults who have developmental language impairments is critical for studies of how such disorders are transmitted through families. In addition, this population is important in its own right, in terms of understanding the long term signs and evolution of the disorder. However, the approaches used to date to identify adults with language impairments have significant flaws. In this proposal, we seek to identify candidate behavioral measures that result in accurate identification of adults with a language impairment. In the absence of a gold standard for identifying these adults, we have adopted an approach that is designed to obtain converging evidence for accurate identification by sampling three populations characterized by high rates of poor language skills. These includes a) adults who received services during childhood, b) adults currently receiving academic support services for language based learning disabilities, and c) parents of children with specific language impairment. A set of tests and experimental tasks will be evaluated for their potential to correctly classify these adults and control subjects. These measures cover classic areas of impairment seen in children with specific language impairment, in both the expressive and receptive language domains. However, in order to detect the more subtle or residual deficits in adult subjects, we have selected or developed tasks that reflect late-developing or complex language skills. Successful measures will consist of that subset that produces a high rate of identification for each of the three target populations (sensitivity) and a low rate of identification of control subjects. In addition, we will evaluate potential sources of bias in identification (either under- or over-identification) associated with demographic characteristics. Given the diversity of the target clinical populations, the resulting identification battery should have utility with a broad selection of the population of adults with language impairments. [unreadable] [unreadable] Relevance: This work addresses a need for accurate identification of adults with developmental language impairments. This is a critical first step for genetic studies of this disorder, as well as research into the longterm outcome of this disorder and the residual deficits that characterize affected adults. [unreadable] [unreadable] [unreadable]